In a warp-thread drawing-in machine disclosed in U.S. Pat. No. 3,681,825 and GB-A-1,290,385, the individual functions are controlled and therefore positively interlinked via mechanical members such as lifters, plate cams and the like. Individual functional steps cannot be performed autonomously and independently of the other functional steps. Instead, a cycle comprising all functions always occurs. The result of this is that faulty operations of individual functional stages cannot be repeated and thus automatically corrected. Such faulty operations either have to be tolerated or repairs must be made manually during a machine stoppage.
If, for example, an individual heald is not correctly separated from a supply stack of healds, the separating operation cannot be repeated two or three times, since during this process the drawing-in member would of course perform a corresponding number of drawing-in operations and the reed would be transported further by a corresponding number of teeth. But separating faults of this type repeatedly occur in practice and thus lead to a reduction in productivity.